1. Field of the Invention
The present invention relates to a snap-in mount for mounting a generally cylindrical body of a device such as a cam lock in holes formed through support panels that differ in thickness. More particularly, the present invention relates to a generally cylindrical body of a cam lock or the like that defines a shoulder for facing toward and engaging one side of a support panel, and that defines an insertion portion which extends away from the shoulder and is configured to be moved along an axis of and inserted through a panel mounting hole, with a plurality of arms being connected to the body for defining arm portions that spring radially outwardly from the insertion portion after the insertion portion hats been inserted through the hole to provide engagement surfaces for engaging the opposite side of the panel, with the engagement surfaces being located at differing distances from a plane in which the shoulder engages the one side of the support panel so that the body can be securely mounted on panels having thicknesses that substantially equal one of these differing distances.
2. Prior Art
Snap-in mounting arrangements for installing small devices such as latches, locks, indicator lights, electrical switches and the like in holes formed through support panels are well known. Often the device to be installed has a generally cylindrical body with a bezel or other type of body formation that defines a shoulder for facing toward and engaging one side of a support panel, with the opposite side of the support panel being engaged by elements that are movably carried by the body and biased to snap radially outwardly after being inserted at least part way through a support panel hole.
Some previously proposed snap-in mounts employ a pair of opposed, radially outwardly biased elements such as arms that are formed integrally with a body that is molded from plastics material, wherein the arms take advantage of the so-called xe2x80x9cmemoryxe2x80x9d of the plastics material to provide a biasing action that is sufficient to snap the arms radially outwardly (after the arms have passed at least part way through a mounting hole formed in a support panel during installation of the body on the support panel), whereafter the arms are retained by the xe2x80x9cmemoryxe2x80x9d of the material in their outwardly extended positions where they engage the rear face of the support panel. These xe2x80x9csnap-outxe2x80x9d elements typically are connected to other portions of the body by regions of relatively thin cross-section that can be flexed to permit the elements to move radially inwardly a sufficient amount to permit passage through a mounting hole. Since the thin cross-sections normally are flexed only once (or only a very limited number of times) during installation of the body on a support panel, the flexed cross-sections usually do not break, and usually retain sufficient strength to be capable of retaining the snap-out elements in their radially outwardly extended positions for holding their associated devices in installed positions on support panels throughout relatively lengthy service lives.
In an effort to accommodate support panels of slightly differing thicknesses, it also is known to provide each of the snap-out elements (of the snap-in mounts of devices to be installed in mounting holes formed through the support panels) with a rack of small tooth-like formations. The tooth-like formations do not feature a design that is optimized for use with a particular panel thickness; rather, these formations are intended to grip, as best they can, support panels within a narrow range of thicknesses, typically to accommodate a range of tolerances such as may be needed if support panels intended to be of generally the same thickness are being provided by a plurality of suppliers. Thus, one drawback associated with utilizing sets of small tooth-like formations on the snap-out elements of a snap-in mount is the fact that the xe2x80x9cteethxe2x80x9d do not feature a design that is optimized to work with any particular support panel thickness. A further drawback resides in the fact that the range of panel thicknesses that the tooth formations are designed to serve usually is quite limited, whereby panel thicknesses that vary significantly one from another are not well accommodated by this approach.
A further limitation that results from utilizing sets or racks of small tooth-like formations on the snap-out elements of snap-in mounts is that the small size of the teeth, and the fact that relatively few of the teeth actually grip a support panel, can cause the resulting grip of the device on the support panel to be lacking in xe2x80x9cmeat.xe2x80x9d Weak grips provided by small teeth can loosen with time as the plastic material from which the teeth are formed tends to wear away, with sharp edges that may enhance the grip tending to xe2x80x9cround offxe2x80x9d so as to conform better to the shape of the panel that is being gripped by the teeth. The resulting relatively weak grips often can be defeated by force, which can permit security devices such as cam locks and switch locks to be pulled from their mounting positions so that the functions they serve can be defeated or bypassed.
Still another problem often not well addressed by the snap-in mounts of prior proposals is the fact that inexpensively formed mounting holes formed in support panels of lockable thermostat covers (and other kinds of low-security equipment covers and the like) can vary significantly in size, which may cause the bodies of devices installed in these holes to fit quite loosely. Undesirable movements and rattling noise may result during use, especially in the presence of vibration. The use of only one pair of oppositely biased snap-out elements that engage only small regions of a support panel at locations on opposite sides of a mounting hole may serve to limit body movement in the opposite directions (that reside within a plane that includes the opposite directions) in which the elements are biased, but tends to do little to limit vibratory movements of the body in other directions (i.e., in directions that are transverse to the plane that contains the opposite directions in which the snap-out elements are biased by the xe2x80x9cmemoryxe2x80x9d of the plastics material from which these elements are formed). While some proposals call for the use of auxiliary biasing devices such as springs to intensify the biasing action in an effort to minimize vibration, the fact that the resulting biasing action operates only in a single plane (namely the plane that contains the opposite directions of the biasing action of the oppositely biased pair of snap-out elements) still does little to quell body movements in directions that are transverse thereto.
The present invention addresses the foregoing and other needs and drawbacks by providing a snap-in mount for mounting a generally cylindrical body of a device such as a cam lock, a switch lock, an indicator light or the like in holes formed through support panels that differ in thickness. In one form of the invention, the body is configured to define a shoulder for facing toward and engaging one side of a support panel, and an insertion portion which extends away from the shoulder and is configured to be moved along an axis of and inserted through a panel mounting hole. A plurality of arms are connected to the body for defining arm portions that spring radially outwardly from the insertion portion after the insertion portion has been inserted through the hole to provide engagement surfaces for engaging the opposite side of the panel. The engagement surfaces are located at differing distances from a plane in which the shoulder engages the one side of the support panel so that the body can be securely mounted on panels having thicknesses that substantially equal one of these differing distances.
In another form of the invention, a snap-in mount is provided for a device that adapts a body of the device to be mounted from one side of and through a: hole formed in a support panel to secure the device to the panel. A shoulder of the device faces in one direction toward the panel for engaging the one side of the panel. A plurality of engagement surfaces also are defined by the device that face in an opposite direction for engaging an opposite side of the panel when the shoulder engages the one side of the panel, with distances between the engagement surfaces and a plane in which the shoulder engages the one side of the panel differing sufficiently to enable the device to be mounted on panels of distinctly different thicknesses. The body of the device has an insertion portion that is configured to be positioned and moved along an axis of the hole so as to be inserted through the hole from the one side of the panel to an installed position where the shoulder of the device faces toward and engages the one side of the panel. A plurality of sets of arms are connected to the body, with each of the arms having an arm portion that is movable inwardly toward the axis and outwardly away from the axis when the body is positioned along the axis. Each of the arm portions is configured, when moved inwardly toward the axis, to pass at least part way through the hole when the insertion portion of the body is moved along the axis to the installed position. Each of the arm portions is configured, when moved outwardly away from the axis, to define an engagement surface that faces in the one direction toward said plane. The engagement surfaces defined by the arm portions of one of the sets of arms are spaced a substantially equal distance from said plane that differs from another distance at which the engagement surfaces defined by the arm portions of at least one of the other sets of arms is spaced from said plane. The arms are connected to the body in a manner that causes the arm portions to normally extend outwardly from the insertion portion of the body to positions located away from the axis, and in a manner that causes the arm portions to be biased toward these extended positions when the arm portions are pressed inwardly toward the axis to permit the insertion portion of the body to pass through the hole so as to cause the arm portions of at least one of the sets of arms to move outwardly away from the axis once the insertion portion has been moved to the installed position to cause the engagement surfaces thereof to face in said opposite direction toward said opposite side of the panel so that the one and opposite sides of the panel are engaged by the shoulder and by selected ones of the engagement surfaces of such ones of the arm portions as have moved outwardly away from the axis after passing at least part way through the hole. By this arrangement, the device can be securely mounted on panels of differing thicknesses that each substantially equal one of the differing distances.
In another form of the invention, a cam lock has a body 1) that extends along an imaginary central axis, 2) that defines a shoulder which faces in one direction along the axis and extends in a shoulder plane that perpendicularly intersects the axis for engaging one side of a panel on which the cam lock is to be mounted, 3) that has a generally cylindrical insertion portion of the body that extends in said direction along the axis away from the shoulder and that is configured to be inserted into and to pass at least partially through a mounting hole formed through the panel, and 4) that carries arms arranged in opposed pairs on opposite sides of the axis with the arms of one of the pairs being spaced circumferentially about the body from the arms of others of the pairs. The arms define arm portions 1) that travel at least part of the way through the mounting hole when the insertion portion of the body is inserted into the mounting hole to an installed position of the body wherein the shoulder engages the one side of the panel, 2) that are movable radially inwardly and outwardly relative to the body, and 3) that are biased outwardly toward extended positions relative to the body, with the arm portions of each pair of arms being operative when in the extended positions thereof to define engagement surfaces that face in an opposite direction along the axis toward the shoulder plane for engaging an opposite side of the panel, and with the engagement surfaces of one of the pairs of arms extending in at least one plane that perpendicularly intersects the axis at at least one distance from the shoulder plane that differs from at least one other distance at which a plane in which the engagement surfaces of another of the pairs of arms perpendicularly intersects the axis, to thereby enable the engagement surfaces of the one and another pairs of arms to cooperate with the shoulder to grip panels of differing thicknesses when the body is in installed positions in mounting holes defined by said panels of differing thickness.
One novel feature of the present invention resides in the use it makes of a plurality of sets of body-carried snap-out elements to define engagement surfaces that extend in different planes spaced along a central axis of the body from a body-defined shoulder to accommodate support panels of distinctly different thicknesses that substantially equal the distances between the plane of the shoulder and the planes of the engagement surfaces. Other novel features also are present, as is exemplified by the use that may be made of a plurality of sets of outwardly biased snap-out elements to engage support panel material that surrounds mounting holes to minimize vibratory movements of the bodies that are installed in the holes.